Re: [patch] Thumb-2 Instructio relaxation

[Richard Earnshaw <rearnsha at gcc dot gnu dot org>]

On Mon, 2005-08-29 at 17:34, Paul Brook wrote:
> The attached patch implements assembler relaxation for Thumb-2 instructions.
> 
>  There are two different classes of relaxation performed:
> - PC-relative branch, adr and ldr instructions.
> - Other (absolute) immediate operands. The current implementation This 
> currently only knows how to handle literal constants, but I plan on teaching 
> it how to handle symbolic constants.
> 
> I've removed the disassembled insn address matching from thumb32.d because 
> it's a pain to keep consistent, and doesn't seem to provide any benefit. The 
> size if the insn is implicitly checked by checking the hex opcode bytes.
> 
> Tested with cross to arm-none-eabi.
> Ok?
> 
> Paul
> 
> 2005-08-28  Paul Brook  <paul@codesourcery.com>
> 
> gas/
> 	* config/tc-arm.c (arm_it): Add relax field.
> 	(T16_32_TAB): Add addi, addis, add_pc, add_sp, dec_sp, inc_sp,
> 	b, bcond, ldr_pc, ldr_pc2, ldr_sp, str_sp, subi, subis.
> 	(do_t_add_sub, do_t_addr, do_t_branch, do_t_ldst,
> 	do_t_mov_cmp): Allow relaxation.
> 	(output_relax_insn): New function.
> 	(put_thumb32_insn): New function.
> 	(output_inst): Use new functions.
> 	(md_assemble): Don't throw error on relaxable instructions.
> 	(insns): Change "b" entry from TCE(...) to tCE(...).
> 	(md_estimate_size_before_relax): Return 2.
> 	(md_convert_frag, relax_immediate, relax_adr, relax_addsub,
> 	relax_branch, arm_relax_frag): New functions.
> 	(arm_force_relocation): Return 0 for Thumb-2 immediate operand
> 	relocations.
> 	* config/tc-arm.h (md_convert_frag): Remove definition.
> 	(md_relax_frag): Define.
> 	(arm_relax_frag): Add prototype.
> gas/testsuite/
> 	* gas/arm/thumb2_relax.d: New test.
> 	* gas/arm/thumb2_relax.s: New test.
> 	* gas/arm/thumb32.d: Adjust expected results to include relaxation.
> 	* gas/arm/thumb32.s: Tweak for better coverage of relaxable
> 	instructions.  Remove load/store tests.

OK.

R.